#ifndef __NET_NETLINK_H
  #define __NET_NETLINK_H
  
  #include <linux/types.h>
  #include <linux/netlink.h>

  #include <linux/jiffies.h>

  
  /* ========================================================================
   *         Netlink Messages and Attributes Interface (As Seen On TV)
   * ------------------------------------------------------------------------
   *                          Messages Interface
   * ------------------------------------------------------------------------
   *
   * Message Format:
   *    <--- nlmsg_total_size(payload)  --->
   *    <-- nlmsg_msg_size(payload) ->
   *   +----------+- - -+-------------+- - -+-------- - -
   *   | nlmsghdr | Pad |   Payload   | Pad | nlmsghdr
   *   +----------+- - -+-------------+- - -+-------- - -
   *   nlmsg_data(nlh)---^                   ^
   *   nlmsg_next(nlh)-----------------------+
   *
   * Payload Format:
   *    <---------------------- nlmsg_len(nlh) --------------------->
   *    <------ hdrlen ------>       <- nlmsg_attrlen(nlh, hdrlen) ->
   *   +----------------------+- - -+--------------------------------+
   *   |     Family Header    | Pad |           Attributes           |
   *   +----------------------+- - -+--------------------------------+
   *   nlmsg_attrdata(nlh, hdrlen)---^
   *
   * Data Structures:
   *   struct nlmsghdr			netlink message header
   *
   * Message Construction:
   *   nlmsg_new()			create a new netlink message
   *   nlmsg_put()			add a netlink message to an skb
   *   nlmsg_put_answer()			callback based nlmsg_put()

   *   nlmsg_end()			finalize netlink message

   *   nlmsg_get_pos()			return current position in message
   *   nlmsg_trim()			trim part of message

   *   nlmsg_cancel()			cancel message construction
   *   nlmsg_free()			free a netlink message
   *
   * Message Sending:
   *   nlmsg_multicast()			multicast message to several groups
   *   nlmsg_unicast()			unicast a message to a single socket

   *   nlmsg_notify()			send notification message

   *
   * Message Length Calculations:
   *   nlmsg_msg_size(payload)		length of message w/o padding
   *   nlmsg_total_size(payload)		length of message w/ padding
   *   nlmsg_padlen(payload)		length of padding at tail
   *
   * Message Payload Access:
   *   nlmsg_data(nlh)			head of message payload
   *   nlmsg_len(nlh)			length of message payload
   *   nlmsg_attrdata(nlh, hdrlen)	head of attributes data
   *   nlmsg_attrlen(nlh, hdrlen)		length of attributes data
   *
   * Message Parsing:
   *   nlmsg_ok(nlh, remaining)		does nlh fit into remaining bytes?
   *   nlmsg_next(nlh, remaining)		get next netlink message
   *   nlmsg_parse()			parse attributes of a message
   *   nlmsg_find_attr()			find an attribute in a message
   *   nlmsg_for_each_msg()		loop over all messages
   *   nlmsg_validate()			validate netlink message incl. attrs
   *   nlmsg_for_each_attr()		loop over all attributes
   *

   * Misc:
   *   nlmsg_report()			report back to application?
   *

   * ------------------------------------------------------------------------
   *                          Attributes Interface
   * ------------------------------------------------------------------------
   *
   * Attribute Format:
   *    <------- nla_total_size(payload) ------->
   *    <---- nla_attr_size(payload) ----->
   *   +----------+- - -+- - - - - - - - - +- - -+-------- - -
   *   |  Header  | Pad |     Payload      | Pad |  Header
   *   +----------+- - -+- - - - - - - - - +- - -+-------- - -
   *                     <- nla_len(nla) ->      ^
   *   nla_data(nla)----^                        |
   *   nla_next(nla)-----------------------------'
   *
   * Data Structures:

   *   struct nlattr			netlink attribute header

   *
   * Attribute Construction:

   *   nla_reserve(skb, type, len)	reserve room for an attribute
   *   nla_reserve_nohdr(skb, len)	reserve room for an attribute w/o hdr

   *   nla_put(skb, type, len, data)	add attribute to skb

   *   nla_put_nohdr(skb, len, data)	add attribute w/o hdr

   *   nla_append(skb, len, data)		append data to skb

   *
   * Attribute Construction for Basic Types:
   *   nla_put_u8(skb, type, value)	add u8 attribute to skb
   *   nla_put_u16(skb, type, value)	add u16 attribute to skb
   *   nla_put_u32(skb, type, value)	add u32 attribute to skb
   *   nla_put_u64(skb, type, value)	add u64 attribute to skb
   *   nla_put_string(skb, type, str)	add string attribute to skb
   *   nla_put_flag(skb, type)		add flag attribute to skb
   *   nla_put_msecs(skb, type, jiffies)	add msecs attribute to skb
   *
   * Exceptions Based Attribute Construction:
   *   NLA_PUT(skb, type, len, data)	add attribute to skb
   *   NLA_PUT_U8(skb, type, value)	add u8 attribute to skb
   *   NLA_PUT_U16(skb, type, value)	add u16 attribute to skb
   *   NLA_PUT_U32(skb, type, value)	add u32 attribute to skb
   *   NLA_PUT_U64(skb, type, value)	add u64 attribute to skb
   *   NLA_PUT_STRING(skb, type, str)	add string attribute to skb
   *   NLA_PUT_FLAG(skb, type)		add flag attribute to skb
   *   NLA_PUT_MSECS(skb, type, jiffies)	add msecs attribute to skb
   *
   *   The meaning of these functions is equal to their lower case
   *   variants but they jump to the label nla_put_failure in case
   *   of a failure.
   *
   * Nested Attributes Construction:
   *   nla_nest_start(skb, type)		start a nested attribute
   *   nla_nest_end(skb, nla)		finalize a nested attribute
   *   nla_nest_cancel(skb, nla)		cancel nested attribute construction
   *
   * Attribute Length Calculations:
   *   nla_attr_size(payload)		length of attribute w/o padding
   *   nla_total_size(payload)		length of attribute w/ padding
   *   nla_padlen(payload)		length of padding
   *
   * Attribute Payload Access:
   *   nla_data(nla)			head of attribute payload
   *   nla_len(nla)			length of attribute payload
   *
   * Attribute Payload Access for Basic Types:
   *   nla_get_u8(nla)			get payload for a u8 attribute
   *   nla_get_u16(nla)			get payload for a u16 attribute
   *   nla_get_u32(nla)			get payload for a u32 attribute
   *   nla_get_u64(nla)			get payload for a u64 attribute
   *   nla_get_flag(nla)			return 1 if flag is true
   *   nla_get_msecs(nla)			get payload for a msecs attribute
   *
   * Attribute Misc:
   *   nla_memcpy(dest, nla, count)	copy attribute into memory
   *   nla_memcmp(nla, data, size)	compare attribute with memory area
   *   nla_strlcpy(dst, nla, size)	copy attribute to a sized string
   *   nla_strcmp(nla, str)		compare attribute with string
   *
   * Attribute Parsing:
   *   nla_ok(nla, remaining)		does nla fit into remaining bytes?
   *   nla_next(nla, remaining)		get next netlink attribute
   *   nla_validate()			validate a stream of attributes

   *   nla_validate_nested()		validate a stream of nested attributes

   *   nla_find()				find attribute in stream of attributes

   *   nla_find_nested()			find attribute in nested attributes

   *   nla_parse()			parse and validate stream of attrs
   *   nla_parse_nested()			parse nested attribuets
   *   nla_for_each_attr()		loop over all attributes

   *   nla_for_each_nested()		loop over the nested attributes

   *=========================================================================
   */
  
   /**
    * Standard attribute types to specify validation policy
    */
  enum {
  	NLA_UNSPEC,
  	NLA_U8,
  	NLA_U16,
  	NLA_U32,
  	NLA_U64,
  	NLA_STRING,
  	NLA_FLAG,
  	NLA_MSECS,
  	NLA_NESTED,

  	NLA_NESTED_COMPAT,

  	NLA_NUL_STRING,

  	NLA_BINARY,

  	__NLA_TYPE_MAX,
  };
  
  #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
  
  /**
   * struct nla_policy - attribute validation policy
   * @type: Type of attribute or NLA_UNSPEC

   * @len: Type specific length of payload

   *
   * Policies are defined as arrays of this struct, the array must be
   * accessible by attribute type up to the highest identifier to be expected.
   *

   * Meaning of `len' field:
   *    NLA_STRING           Maximum length of string
   *    NLA_NUL_STRING       Maximum length of string (excluding NUL)
   *    NLA_FLAG             Unused

   *    NLA_BINARY           Maximum length of attribute payload

   *    NLA_NESTED           Don't use `len' field -- length verification is
   *                         done by checking len of nested header (or empty)
   *    NLA_NESTED_COMPAT    Minimum length of structure payload
   *    NLA_U8, NLA_U16,
   *    NLA_U32, NLA_U64,
   *    NLA_MSECS            Leaving the length field zero will verify the
   *                         given type fits, using it verifies minimum length
   *                         just like "All other"
   *    All other            Minimum length of attribute payload

   *

   * Example:

   * static const struct nla_policy my_policy[ATTR_MAX+1] = {

   * 	[ATTR_FOO] = { .type = NLA_U16 },

   *	[ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },

   *	[ATTR_BAZ] = { .len = sizeof(struct mystruct) },

   * };
   */
  struct nla_policy {
  	u16		type;

  	u16		len;

  };

  /**
   * struct nl_info - netlink source information
   * @nlh: Netlink message header of original request
   * @pid: Netlink PID of requesting application
   */
  struct nl_info {
  	struct nlmsghdr		*nlh;

  	struct net		*nl_net;

  	u32			pid;
  };

  extern int		netlink_rcv_skb(struct sk_buff *skb,
  					int (*cb)(struct sk_buff *,
  						  struct nlmsghdr *));

  extern int		nlmsg_notify(struct sock *sk, struct sk_buff *skb,
  				     u32 pid, unsigned int group, int report,
  				     gfp_t flags);

  extern int		nla_validate(const struct nlattr *head,
  				     int len, int maxtype,

  				     const struct nla_policy *policy);

  extern int		nla_parse(struct nlattr **tb, int maxtype,
  				  const struct nlattr *head, int len,

  				  const struct nla_policy *policy);

  extern int		nla_policy_len(const struct nla_policy *, int);

  extern struct nlattr *	nla_find(const struct nlattr *head,
  				 int len, int attrtype);

  extern size_t		nla_strlcpy(char *dst, const struct nlattr *nla,
  				    size_t dstsize);

  extern int		nla_memcpy(void *dest, const struct nlattr *src, int count);

  extern int		nla_memcmp(const struct nlattr *nla, const void *data,
  				   size_t size);
  extern int		nla_strcmp(const struct nlattr *nla, const char *str);
  extern struct nlattr *	__nla_reserve(struct sk_buff *skb, int attrtype,
  				      int attrlen);

  extern void *		__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);

  extern struct nlattr *	nla_reserve(struct sk_buff *skb, int attrtype,
  				    int attrlen);

  extern void *		nla_reserve_nohdr(struct sk_buff *skb, int attrlen);

  extern void		__nla_put(struct sk_buff *skb, int attrtype,
  				  int attrlen, const void *data);

  extern void		__nla_put_nohdr(struct sk_buff *skb, int attrlen,
  					const void *data);

  extern int		nla_put(struct sk_buff *skb, int attrtype,
  				int attrlen, const void *data);

  extern int		nla_put_nohdr(struct sk_buff *skb, int attrlen,
  				      const void *data);

  extern int		nla_append(struct sk_buff *skb, int attrlen,
  				   const void *data);

  
  /**************************************************************************
   * Netlink Messages
   **************************************************************************/
  
  /**
   * nlmsg_msg_size - length of netlink message not including padding
   * @payload: length of message payload
   */
  static inline int nlmsg_msg_size(int payload)
  {
  	return NLMSG_HDRLEN + payload;
  }
  
  /**
   * nlmsg_total_size - length of netlink message including padding
   * @payload: length of message payload
   */
  static inline int nlmsg_total_size(int payload)
  {
  	return NLMSG_ALIGN(nlmsg_msg_size(payload));
  }
  
  /**
   * nlmsg_padlen - length of padding at the message's tail
   * @payload: length of message payload
   */
  static inline int nlmsg_padlen(int payload)
  {
  	return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
  }
  
  /**
   * nlmsg_data - head of message payload

   * @nlh: netlink message header

   */
  static inline void *nlmsg_data(const struct nlmsghdr *nlh)
  {
  	return (unsigned char *) nlh + NLMSG_HDRLEN;
  }
  
  /**
   * nlmsg_len - length of message payload
   * @nlh: netlink message header
   */
  static inline int nlmsg_len(const struct nlmsghdr *nlh)
  {
  	return nlh->nlmsg_len - NLMSG_HDRLEN;
  }
  
  /**
   * nlmsg_attrdata - head of attributes data
   * @nlh: netlink message header
   * @hdrlen: length of family specific header
   */
  static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
  					    int hdrlen)
  {
  	unsigned char *data = nlmsg_data(nlh);
  	return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
  }
  
  /**
   * nlmsg_attrlen - length of attributes data
   * @nlh: netlink message header
   * @hdrlen: length of family specific header
   */
  static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
  {
  	return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
  }
  
  /**
   * nlmsg_ok - check if the netlink message fits into the remaining bytes
   * @nlh: netlink message header
   * @remaining: number of bytes remaining in message stream
   */
  static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
  {

  	return (remaining >= (int) sizeof(struct nlmsghdr) &&

  		nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
  		nlh->nlmsg_len <= remaining);
  }
  
  /**
   * nlmsg_next - next netlink message in message stream
   * @nlh: netlink message header
   * @remaining: number of bytes remaining in message stream
   *
   * Returns the next netlink message in the message stream and
   * decrements remaining by the size of the current message.
   */

  static inline struct nlmsghdr *
  nlmsg_next(const struct nlmsghdr *nlh, int *remaining)

  {
  	int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
  
  	*remaining -= totlen;
  
  	return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
  }
  
  /**
   * nlmsg_parse - parse attributes of a netlink message
   * @nlh: netlink message header
   * @hdrlen: length of family specific header
   * @tb: destination array with maxtype+1 elements
   * @maxtype: maximum attribute type to be expected
   * @policy: validation policy
   *
   * See nla_parse()
   */

  static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,

  			      struct nlattr *tb[], int maxtype,

  			      const struct nla_policy *policy)

  {
  	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
  		return -EINVAL;
  
  	return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
  			 nlmsg_attrlen(nlh, hdrlen), policy);
  }
  
  /**
   * nlmsg_find_attr - find a specific attribute in a netlink message
   * @nlh: netlink message header
   * @hdrlen: length of familiy specific header
   * @attrtype: type of attribute to look for
   *
   * Returns the first attribute which matches the specified type.
   */

  static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,

  					     int hdrlen, int attrtype)
  {
  	return nla_find(nlmsg_attrdata(nlh, hdrlen),
  			nlmsg_attrlen(nlh, hdrlen), attrtype);
  }
  
  /**
   * nlmsg_validate - validate a netlink message including attributes
   * @nlh: netlinket message header
   * @hdrlen: length of familiy specific header
   * @maxtype: maximum attribute type to be expected
   * @policy: validation policy
   */

  static inline int nlmsg_validate(const struct nlmsghdr *nlh,
  				 int hdrlen, int maxtype,

  				 const struct nla_policy *policy)

  {
  	if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
  		return -EINVAL;
  
  	return nla_validate(nlmsg_attrdata(nlh, hdrlen),
  			    nlmsg_attrlen(nlh, hdrlen), maxtype, policy);
  }
  
  /**

   * nlmsg_report - need to report back to application?
   * @nlh: netlink message header
   *
   * Returns 1 if a report back to the application is requested.
   */

  static inline int nlmsg_report(const struct nlmsghdr *nlh)

  {
  	return !!(nlh->nlmsg_flags & NLM_F_ECHO);
  }
  
  /**

   * nlmsg_for_each_attr - iterate over a stream of attributes
   * @pos: loop counter, set to current attribute
   * @nlh: netlink message header
   * @hdrlen: length of familiy specific header
   * @rem: initialized to len, holds bytes currently remaining in stream
   */
  #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
  	nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
  			  nlmsg_attrlen(nlh, hdrlen), rem)
  
  #if 0
  /* FIXME: Enable once all users have been converted */
  
  /**
   * __nlmsg_put - Add a new netlink message to an skb
   * @skb: socket buffer to store message in
   * @pid: netlink process id
   * @seq: sequence number of message
   * @type: message type
   * @payload: length of message payload
   * @flags: message flags
   *
   * The caller is responsible to ensure that the skb provides enough
   * tailroom for both the netlink header and payload.
   */
  static inline struct nlmsghdr *__nlmsg_put(struct sk_buff *skb, u32 pid,
  					   u32 seq, int type, int payload,
  					   int flags)
  {
  	struct nlmsghdr *nlh;
  
  	nlh = (struct nlmsghdr *) skb_put(skb, nlmsg_total_size(payload));
  	nlh->nlmsg_type = type;
  	nlh->nlmsg_len = nlmsg_msg_size(payload);
  	nlh->nlmsg_flags = flags;
  	nlh->nlmsg_pid = pid;
  	nlh->nlmsg_seq = seq;
  
  	memset((unsigned char *) nlmsg_data(nlh) + payload, 0,
  	       nlmsg_padlen(payload));
  
  	return nlh;
  }
  #endif
  
  /**
   * nlmsg_put - Add a new netlink message to an skb
   * @skb: socket buffer to store message in
   * @pid: netlink process id
   * @seq: sequence number of message
   * @type: message type
   * @payload: length of message payload
   * @flags: message flags
   *
   * Returns NULL if the tailroom of the skb is insufficient to store
   * the message header and payload.
   */
  static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
  					 int type, int payload, int flags)
  {
  	if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
  		return NULL;
  
  	return __nlmsg_put(skb, pid, seq, type, payload, flags);
  }
  
  /**
   * nlmsg_put_answer - Add a new callback based netlink message to an skb
   * @skb: socket buffer to store message in
   * @cb: netlink callback
   * @type: message type
   * @payload: length of message payload
   * @flags: message flags
   *
   * Returns NULL if the tailroom of the skb is insufficient to store
   * the message header and payload.
   */
  static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
  						struct netlink_callback *cb,
  						int type, int payload,
  						int flags)
  {
  	return nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
  			 type, payload, flags);
  }
  
  /**
   * nlmsg_new - Allocate a new netlink message

   * @payload: size of the message payload

   * @flags: the type of memory to allocate.

   *

   * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
   * and a good default is needed.

   */

  static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)

  {

  	return alloc_skb(nlmsg_total_size(payload), flags);

  }
  
  /**
   * nlmsg_end - Finalize a netlink message
   * @skb: socket buffer the message is stored in
   * @nlh: netlink message header
   *
   * Corrects the netlink message header to include the appeneded
   * attributes. Only necessary if attributes have been added to
   * the message.
   *
   * Returns the total data length of the skb.
   */
  static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
  {

  	nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;

  
  	return skb->len;
  }
  
  /**

   * nlmsg_get_pos - return current position in netlink message
   * @skb: socket buffer the message is stored in
   *
   * Returns a pointer to the current tail of the message.
   */
  static inline void *nlmsg_get_pos(struct sk_buff *skb)
  {

  	return skb_tail_pointer(skb);

  }
  
  /**
   * nlmsg_trim - Trim message to a mark
   * @skb: socket buffer the message is stored in
   * @mark: mark to trim to
   *

   * Trims the message to the provided mark.

   */

  static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)

  {
  	if (mark)
  		skb_trim(skb, (unsigned char *) mark - skb->data);

  }
  
  /**

   * nlmsg_cancel - Cancel construction of a netlink message
   * @skb: socket buffer the message is stored in
   * @nlh: netlink message header
   *
   * Removes the complete netlink message including all

   * attributes from the socket buffer again.

   */

  static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)

  {

  	nlmsg_trim(skb, nlh);

  }
  
  /**
   * nlmsg_free - free a netlink message
   * @skb: socket buffer of netlink message
   */
  static inline void nlmsg_free(struct sk_buff *skb)
  {
  	kfree_skb(skb);
  }
  
  /**
   * nlmsg_multicast - multicast a netlink message
   * @sk: netlink socket to spread messages to
   * @skb: netlink message as socket buffer
   * @pid: own netlink pid to avoid sending to yourself
   * @group: multicast group id

   * @flags: allocation flags

   */
  static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,

  				  u32 pid, unsigned int group, gfp_t flags)

  {
  	int err;
  
  	NETLINK_CB(skb).dst_group = group;

  	err = netlink_broadcast(sk, skb, pid, group, flags);

  	if (err > 0)
  		err = 0;
  
  	return err;
  }
  
  /**
   * nlmsg_unicast - unicast a netlink message
   * @sk: netlink socket to spread message to
   * @skb: netlink message as socket buffer
   * @pid: netlink pid of the destination socket
   */
  static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 pid)
  {
  	int err;
  
  	err = netlink_unicast(sk, skb, pid, MSG_DONTWAIT);
  	if (err > 0)
  		err = 0;
  
  	return err;
  }
  
  /**
   * nlmsg_for_each_msg - iterate over a stream of messages
   * @pos: loop counter, set to current message
   * @head: head of message stream
   * @len: length of message stream
   * @rem: initialized to len, holds bytes currently remaining in stream
   */
  #define nlmsg_for_each_msg(pos, head, len, rem) \
  	for (pos = head, rem = len; \
  	     nlmsg_ok(pos, rem); \
  	     pos = nlmsg_next(pos, &(rem)))

  /**
   * nl_dump_check_consistent - check if sequence is consistent and advertise if not
   * @cb: netlink callback structure that stores the sequence number
   * @nlh: netlink message header to write the flag to
   *
   * This function checks if the sequence (generation) number changed during dump
   * and if it did, advertises it in the netlink message header.
   *
   * The correct way to use it is to set cb->seq to the generation counter when
   * all locks for dumping have been acquired, and then call this function for
   * each message that is generated.
   *
   * Note that due to initialisation concerns, 0 is an invalid sequence number
   * and must not be used by code that uses this functionality.
   */
  static inline void
  nl_dump_check_consistent(struct netlink_callback *cb,
  			 struct nlmsghdr *nlh)
  {
  	if (cb->prev_seq && cb->seq != cb->prev_seq)
  		nlh->nlmsg_flags |= NLM_F_DUMP_INTR;
  	cb->prev_seq = cb->seq;
  }

  /**************************************************************************
   * Netlink Attributes
   **************************************************************************/
  
  /**
   * nla_attr_size - length of attribute not including padding
   * @payload: length of payload
   */
  static inline int nla_attr_size(int payload)
  {
  	return NLA_HDRLEN + payload;
  }
  
  /**
   * nla_total_size - total length of attribute including padding
   * @payload: length of payload
   */
  static inline int nla_total_size(int payload)
  {
  	return NLA_ALIGN(nla_attr_size(payload));
  }
  
  /**
   * nla_padlen - length of padding at the tail of attribute
   * @payload: length of payload
   */
  static inline int nla_padlen(int payload)
  {
  	return nla_total_size(payload) - nla_attr_size(payload);
  }
  
  /**

   * nla_type - attribute type
   * @nla: netlink attribute
   */
  static inline int nla_type(const struct nlattr *nla)
  {
  	return nla->nla_type & NLA_TYPE_MASK;
  }
  
  /**

   * nla_data - head of payload
   * @nla: netlink attribute
   */
  static inline void *nla_data(const struct nlattr *nla)
  {
  	return (char *) nla + NLA_HDRLEN;
  }
  
  /**
   * nla_len - length of payload
   * @nla: netlink attribute
   */
  static inline int nla_len(const struct nlattr *nla)
  {
  	return nla->nla_len - NLA_HDRLEN;
  }
  
  /**
   * nla_ok - check if the netlink attribute fits into the remaining bytes
   * @nla: netlink attribute
   * @remaining: number of bytes remaining in attribute stream
   */
  static inline int nla_ok(const struct nlattr *nla, int remaining)
  {

  	return remaining >= (int) sizeof(*nla) &&

  	       nla->nla_len >= sizeof(*nla) &&
  	       nla->nla_len <= remaining;
  }
  
  /**

   * nla_next - next netlink attribute in attribute stream

   * @nla: netlink attribute
   * @remaining: number of bytes remaining in attribute stream
   *
   * Returns the next netlink attribute in the attribute stream and
   * decrements remaining by the size of the current attribute.
   */
  static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
  {
  	int totlen = NLA_ALIGN(nla->nla_len);
  
  	*remaining -= totlen;
  	return (struct nlattr *) ((char *) nla + totlen);
  }
  
  /**

   * nla_find_nested - find attribute in a set of nested attributes
   * @nla: attribute containing the nested attributes
   * @attrtype: type of attribute to look for
   *
   * Returns the first attribute which matches the specified type.
   */

  static inline struct nlattr *
  nla_find_nested(const struct nlattr *nla, int attrtype)

  {
  	return nla_find(nla_data(nla), nla_len(nla), attrtype);
  }
  
  /**

   * nla_parse_nested - parse nested attributes
   * @tb: destination array with maxtype+1 elements
   * @maxtype: maximum attribute type to be expected
   * @nla: attribute containing the nested attributes
   * @policy: validation policy
   *
   * See nla_parse()
   */
  static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,

  				   const struct nlattr *nla,

  				   const struct nla_policy *policy)

  {
  	return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy);
  }

  
  /**

   * nla_put_u8 - Add a u8 netlink attribute to a socket buffer

   * @skb: socket buffer to add attribute to
   * @attrtype: attribute type
   * @value: numeric value
   */
  static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value)
  {
  	return nla_put(skb, attrtype, sizeof(u8), &value);
  }
  
  /**
   * nla_put_u16 - Add a u16 netlink attribute to a socket buffer
   * @skb: socket buffer to add attribute to
   * @attrtype: attribute type
   * @value: numeric value
   */
  static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value)
  {
  	return nla_put(skb, attrtype, sizeof(u16), &value);
  }
  
  /**
   * nla_put_u32 - Add a u32 netlink attribute to a socket buffer
   * @skb: socket buffer to add attribute to
   * @attrtype: attribute type
   * @value: numeric value
   */
  static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value)
  {
  	return nla_put(skb, attrtype, sizeof(u32), &value);
  }
  
  /**
   * nla_put_64 - Add a u64 netlink attribute to a socket buffer
   * @skb: socket buffer to add attribute to
   * @attrtype: attribute type
   * @value: numeric value
   */
  static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value)
  {
  	return nla_put(skb, attrtype, sizeof(u64), &value);
  }
  
  /**
   * nla_put_string - Add a string netlink attribute to a socket buffer
   * @skb: socket buffer to add attribute to
   * @attrtype: attribute type
   * @str: NUL terminated string
   */
  static inline int nla_put_string(struct sk_buff *skb, int attrtype,
  				 const char *str)
  {
  	return nla_put(skb, attrtype, strlen(str) + 1, str);
  }
  
  /**
   * nla_put_flag - Add a flag netlink attribute to a socket buffer
   * @skb: socket buffer to add attribute to
   * @attrtype: attribute type
   */
  static inline int nla_put_flag(struct sk_buff *skb, int attrtype)
  {
  	return nla_put(skb, attrtype, 0, NULL);
  }
  
  /**
   * nla_put_msecs - Add a msecs netlink attribute to a socket buffer
   * @skb: socket buffer to add attribute to
   * @attrtype: attribute type
   * @jiffies: number of msecs in jiffies
   */
  static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
  				unsigned long jiffies)
  {
  	u64 tmp = jiffies_to_msecs(jiffies);
  	return nla_put(skb, attrtype, sizeof(u64), &tmp);
  }
  
  #define NLA_PUT(skb, attrtype, attrlen, data) \
  	do { \

  		if (unlikely(nla_put(skb, attrtype, attrlen, data) < 0)) \

  			goto nla_put_failure; \
  	} while(0)
  
  #define NLA_PUT_TYPE(skb, type, attrtype, value) \
  	do { \
  		type __tmp = value; \
  		NLA_PUT(skb, attrtype, sizeof(type), &__tmp); \
  	} while(0)
  
  #define NLA_PUT_U8(skb, attrtype, value) \
  	NLA_PUT_TYPE(skb, u8, attrtype, value)
  
  #define NLA_PUT_U16(skb, attrtype, value) \
  	NLA_PUT_TYPE(skb, u16, attrtype, value)

  #define NLA_PUT_LE16(skb, attrtype, value) \
  	NLA_PUT_TYPE(skb, __le16, attrtype, value)

  #define NLA_PUT_BE16(skb, attrtype, value) \
  	NLA_PUT_TYPE(skb, __be16, attrtype, value)

  #define NLA_PUT_NET16(skb, attrtype, value) \
  	NLA_PUT_BE16(skb, attrtype | NLA_F_NET_BYTEORDER, value)

  #define NLA_PUT_U32(skb, attrtype, value) \
  	NLA_PUT_TYPE(skb, u32, attrtype, value)

  #define NLA_PUT_BE32(skb, attrtype, value) \
  	NLA_PUT_TYPE(skb, __be32, attrtype, value)

  #define NLA_PUT_NET32(skb, attrtype, value) \
  	NLA_PUT_BE32(skb, attrtype | NLA_F_NET_BYTEORDER, value)

  #define NLA_PUT_U64(skb, attrtype, value) \
  	NLA_PUT_TYPE(skb, u64, attrtype, value)

  #define NLA_PUT_BE64(skb, attrtype, value) \
  	NLA_PUT_TYPE(skb, __be64, attrtype, value)

  #define NLA_PUT_NET64(skb, attrtype, value) \
  	NLA_PUT_BE64(skb, attrtype | NLA_F_NET_BYTEORDER, value)

  #define NLA_PUT_STRING(skb, attrtype, value) \
  	NLA_PUT(skb, attrtype, strlen(value) + 1, value)

  #define NLA_PUT_FLAG(skb, attrtype) \

  	NLA_PUT(skb, attrtype, 0, NULL)
  
  #define NLA_PUT_MSECS(skb, attrtype, jiffies) \
  	NLA_PUT_U64(skb, attrtype, jiffies_to_msecs(jiffies))
  
  /**
   * nla_get_u32 - return payload of u32 attribute
   * @nla: u32 netlink attribute
   */

  static inline u32 nla_get_u32(const struct nlattr *nla)

  {
  	return *(u32 *) nla_data(nla);
  }
  
  /**

   * nla_get_be32 - return payload of __be32 attribute
   * @nla: __be32 netlink attribute
   */

  static inline __be32 nla_get_be32(const struct nlattr *nla)

  {
  	return *(__be32 *) nla_data(nla);
  }
  
  /**

   * nla_get_u16 - return payload of u16 attribute
   * @nla: u16 netlink attribute
   */

  static inline u16 nla_get_u16(const struct nlattr *nla)

  {
  	return *(u16 *) nla_data(nla);
  }
  
  /**

   * nla_get_be16 - return payload of __be16 attribute
   * @nla: __be16 netlink attribute
   */

  static inline __be16 nla_get_be16(const struct nlattr *nla)

  {
  	return *(__be16 *) nla_data(nla);
  }
  
  /**

   * nla_get_le16 - return payload of __le16 attribute
   * @nla: __le16 netlink attribute
   */

  static inline __le16 nla_get_le16(const struct nlattr *nla)

  {
  	return *(__le16 *) nla_data(nla);
  }
  
  /**

   * nla_get_u8 - return payload of u8 attribute
   * @nla: u8 netlink attribute
   */

  static inline u8 nla_get_u8(const struct nlattr *nla)

  {
  	return *(u8 *) nla_data(nla);
  }
  
  /**
   * nla_get_u64 - return payload of u64 attribute
   * @nla: u64 netlink attribute
   */

  static inline u64 nla_get_u64(const struct nlattr *nla)

  {
  	u64 tmp;
  
  	nla_memcpy(&tmp, nla, sizeof(tmp));
  
  	return tmp;
  }
  
  /**

   * nla_get_be64 - return payload of __be64 attribute
   * @nla: __be64 netlink attribute
   */
  static inline __be64 nla_get_be64(const struct nlattr *nla)
  {

  	__be64 tmp;
  
  	nla_memcpy(&tmp, nla, sizeof(tmp));
  
  	return tmp;

  }
  
  /**

   * nla_get_flag - return payload of flag attribute
   * @nla: flag netlink attribute
   */

  static inline int nla_get_flag(const struct nlattr *nla)

  {
  	return !!nla;
  }
  
  /**
   * nla_get_msecs - return payload of msecs attribute
   * @nla: msecs netlink attribute
   *
   * Returns the number of milliseconds in jiffies.
   */

  static inline unsigned long nla_get_msecs(const struct nlattr *nla)

  {
  	u64 msecs = nla_get_u64(nla);
  
  	return msecs_to_jiffies((unsigned long) msecs);
  }
  
  /**
   * nla_nest_start - Start a new level of nested attributes
   * @skb: socket buffer to add attributes to
   * @attrtype: attribute type of container
   *
   * Returns the container attribute
   */
  static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
  {

  	struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);

  
  	if (nla_put(skb, attrtype, 0, NULL) < 0)
  		return NULL;
  
  	return start;
  }
  
  /**
   * nla_nest_end - Finalize nesting of attributes

   * @skb: socket buffer the attributes are stored in

   * @start: container attribute
   *
   * Corrects the container attribute header to include the all
   * appeneded attributes.
   *
   * Returns the total data length of the skb.
   */
  static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
  {

  	start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;

  	return skb->len;
  }
  
  /**
   * nla_nest_cancel - Cancel nesting of attributes
   * @skb: socket buffer the message is stored in
   * @start: container attribute
   *
   * Removes the container attribute and including all nested

   * attributes. Returns -EMSGSIZE

   */

  static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)

  {

  	nlmsg_trim(skb, start);

  }
  
  /**

   * nla_validate_nested - Validate a stream of nested attributes
   * @start: container attribute
   * @maxtype: maximum attribute type to be expected
   * @policy: validation policy
   *
   * Validates all attributes in the nested attribute stream against the
   * specified policy. Attributes with a type exceeding maxtype will be
   * ignored. See documenation of struct nla_policy for more details.
   *
   * Returns 0 on success or a negative error code.
   */

  static inline int nla_validate_nested(const struct nlattr *start, int maxtype,

  				      const struct nla_policy *policy)

  {
  	return nla_validate(nla_data(start), nla_len(start), maxtype, policy);
  }
  
  /**

   * nla_for_each_attr - iterate over a stream of attributes
   * @pos: loop counter, set to current attribute
   * @head: head of attribute stream
   * @len: length of attribute stream
   * @rem: initialized to len, holds bytes currently remaining in stream
   */
  #define nla_for_each_attr(pos, head, len, rem) \
  	for (pos = head, rem = len; \
  	     nla_ok(pos, rem); \
  	     pos = nla_next(pos, &(rem)))

  /**
   * nla_for_each_nested - iterate over nested attributes
   * @pos: loop counter, set to current attribute
   * @nla: attribute containing the nested attributes
   * @rem: initialized to len, holds bytes currently remaining in stream
   */
  #define nla_for_each_nested(pos, nla, rem) \
  	nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)

  #endif